Study of Thoracoscopic Repair of Diaphragmatic Eventration in Children: A Case Series

Introduction

Diaphragmatic eventration (DE) is an abnormal elevation of part or all of the hemidiaphragm commonly involving the left side of the diaphragm. It can be either of congenital or secondary due to birth trauma with cervical distraction, phrenic nerve branches avulsion. Congenital diaphragmatic eventration (CDE) occurs in 0.02–0.07/1000 births with male predominance (60%–80%).^1–3 Decreasing the surface of the redundant diaphragm, increasing its thickness and rigidity by plicating to an acceptable normal level and protecting the phrenic nerve is the principle of operation. The repair of diaphragm improves diaphragmatic movements during respiration thereby achieving a physiological pulmonary function. After unilateral plication the global muscular force of the diaphragm increases and the transdiaphragmatic pressure gain by ∼30%. ⁴

Treatment of CDE includes an open approach or minimal access surgery through an abdominal or thoracic approach with plication or reduction of the redundant diaphragm. Minimal access surgery has the advantage of less postoperative pain and early recovery. The laparoscopic approach provides more space for manipulation and view of the branches of the phrenic nerve. The thoracoscopic route has an advantage of better visualization and less handling of local tissue during plication of the diaphragm. ⁴

In this article we report our results and experience, and highlight few technical points and modifications to prevent complications and recurrence.

Materials and Methods

This is an observational study of patients with DE following CARE guidelines endorsed by EQUATOR Network. Pediatric patients who had undergone thoracoscopic repair between January 2010 and March 2019 were included in the study. Age at surgery, gender, weight, site of lesion, operating time, need for postoperative drain, and complications were assessed. All patients underwent elective thoracoscopy under general anesthesia, positioned head up with a bolster below the ipsilateral thorax thereby displacing intra-abdominal organs downward, which provided easy manipulation of the diaphragm and better view without the need of single lung ventilation. A CO₂ insufflation pressure (2–3 mm Hg) achieved the lung collapse. The optical port was placed at second intercostal space in mid-axillary line (5 mm), the other two ports are placed directly in chest wall one intercostal space below optical port anterior to the anterior axillary line and posterior axillary line. Plication was achieved with continuous horizontal mattress suture starting from the lateral muscular part then plicating the diaphragm up to the medial end and returning to lateral muscular end with intracorporal knotting without using another port. Intraoperative vitals were monitored with EtCO₂ monitoring. intercostal drain (ICD) was placed in cases of inadvertent injury to vessel or lung parenchyma to check for any postoperative discharge or bronchopulmonary fistula. The patient was discharged after removal of ICD and the patient tolerated the feed well. During follow-up, clinical examination and chest X-ray at 1 month after surgery was performed.

Results

A total of 26 patients underwent a thoracoscopic approach for correction of DE. The male–female ratio was 12:1. Mean weight at the time of surgery was 6.3 kg (2.2–22 kg) with most patients having left side CDE (n = 21) as compared with the right side (n = 5). The average operating time was 66 minutes (37–144 minutes) (Table 1).

Immediate complications (Table 2) were subcutaneous emphysema (n = 1), hemothorax (n = 1), and pneumothorax (n = 1). Postoperative 24 patients were extubated in the operative room, whereas 2 patients were extubated on the same day in the recovery room. ICD was placed in 10 patients who were removed on postoperative day 2 or 3. Microscopic bronchopleural fistula due to needle puncture of the lung (n = 2) was observed, which healed spontaneously in 3 days. Subcutaneous emphysema (n = 1) developed during the postoperative period probably due to enlarged port sites treated by ICD. Pneumothorax (n = 1) developed on postoperative day 1 and was treated by ICD insertion. Thoracoscopic repair successful in 24 patients, whereas 2 cases had recurrence after 6 months and 1 year, respectively, which required reoperation, in 1 patient this was done thoracoscopically where the central part of the diaphragm was seen to be floppy and replicated, in the second patent open repair was undertaken. Postoperative chest X-ray at 1 month showed flattening of the diaphragm in all patients. There was no mortality. Mean hospital stay was 5 days and all patients were discharged within a week. During follow-up, X-ray chest and clinical examination were performed. A success rate of 93% was achieved, but we have also experienced two recurrences that were early in the learning curve.

Discussion

The first minimal access surgery in a newborn with CDE was reported by Van Smith et al. ⁵ Decreasing the surface of the redundant diaphragm, increasing its thickness and rigidity by plicating to an acceptable normal level, and protecting the phrenic nerve is the principle of operation. ⁶ Thoracoscopy has been increasingly used in the plication of the diaphragm; however, the efficiency and safety of thoracoscopy in less ventilation impact and better outcome in neonates have been reported in very few reports. ⁷

Very few case reports have been described in the literature for thoracoscopic eventration repair in pediatrics, which is even rare in cases of neonates.^1,2,8,9 Our study included the largest reported series of thoracoscopic repair in pediatrics and neonates highlighting the differences in technique and modifications to prevent complications.

Previous studies suggest placing the patient in lateral decubitus position with block lying in contralateral chest,^3–5 but in our study, patients were positioned head up with a bolster below the I/L thorax that displaces the intra-abdominal organs downward providing a better view and easy manipulation of diaphragm, which was more ergonomic than extreme lateral position. ¹⁰ It also helped in placing the port higher up in the chest preventing inadvertent injury to viscera. Selective ventilation was not used even in older children.

As reported in other series by Abraham et al., carbon dioxide insufflation was useful in our series. ² Hines preferred lung retractors, but it requires one extra port. ¹ Carbon dioxide pressure was kept at 2–3 mm Hg with a minimal flow (max. 1 L/min), which is less than various case series that used the pressure between 6 and 8 mm Hg increasing chance of CO₂ retention and toxicity in cases of neonates. ³ The low insufflation pressure was enough to reduce the lung and obtaining an adequate space for using instruments. CO₂ insufflation also collapses the redundant diaphragm with positive intrathoracic pressure. All this prevents the use of single-lung ventilation with or without bronchial blocker and lung retractors, thereby reducing the need for an extra port. Grasping and pulling the diaphragm confirms the possible adhesion of the abdominal organs. ¹⁰

According to Abraham et al., interrupted sutures may prevent recurrence than running sutures; however, there is no evidence for it. ² In our study, continuous sutures were placed starting from the lateral muscular part then plicating the diaphragm up to medial end and returning to lateral muscular end with intracorporal knotting without using another port (Fig. 1). We did not use endo stapler or resection of a redundant diaphragm, which prevented inadvertent injury to other organs, need for extra port, and was cost-effective as single polypropylene suture was used in the entire procedure of plication. ⁸ It is important to monitor ventilation during the insufflation of carbon dioxide, as any variation of the parameters requires temporarily stopping of carbon dioxide insufflation. Once the contents are reduced insufflation may be stopped to reduce the risk of acidosis. ¹⁰

OPEN IN VIEWER

FIG. 1.

Thoracoscopic view of plication of diaphragm.

During the initial period of our learning curve, there were few intraoperative complications detected postoperatively as shown in Table 2. Infant feeding tube (10 Fr) was inserted from the port site as ICD. As the author gained experience there were no further complications and the ICD was not required. At the end of plication, gentle suction helped to remove residual air in pleural space and re-expanding the lung, which was sufficient in most of the cases and avoided chest drainage and reduces postoperative pain, early recovery, and postoperative physiotherapy.

Conclusions

Diaphragm plication by a thoracoscopic approach is safe and feasible in neonates and pediatric patients with DE. It may provide an alternative method of repair in these cases; however, more studies are required for its wider acceptance.